Mechanical pencil



35, T193. p, 5, HAU-RDN MECHANICAL PENCIL Original Filed Aug. 2l, 1929 HAUTON uNvENToR PAU L. S

EY HIS ATTORNEY E TM ,Elli

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Peienied Feb. 1s, 193s UNITED STATES PATENT OFFICE MECHANICAL PENCIL Paul S. Hauton, Atlanta, Ga.

Claims. (Cl. 1Z0-18) My invention relates to pencils of the mechanical type, having means foradjustably projecting and electing the lead, and is a division of my copending application Serial No. 387,542 filed August 21, 1929.

The purpose of the invention Ais to provide a generally improved, simplified and economical structure, and especially to provide an improved screw or operating helix, guide sleeve, lead grip and ejecting pin.

In pencilsof Lthis class, the operating screw or helix has frequently been in the form of a helical wire or strip with spaced turns, and in such devices the spacing of the turns is liable to alteration after assembly of the pencil. I provide an operating screw or helix consisting of an originally flat straight strip of sheet metal, and coil it into a helix with the strip edges in contact, the strip being cross-sectionally formed to provide a channel; or else I interpose a helical wire between the edges of the strip, so that in either case the turns of the strip are secured against variations in spacing.

I also provide in combination with the operat-v ing screw'and a slotted guide sleeve, a lead grip sleeve therein, and ejecting pin within the grip sleeve, and lugs on the grip sleeve and pin engaging the helix of the screw, together with a sleeve near the vtip end of the pencil case or body and arranged to receive the grip sleeve lug while the sleeve is in ejecting position. II'he guide sleeve ls also arranged to have frictionalV cooperation with the grip sleeve lug to secure the proper relative positioning of the grip sleeve and ejecting pin as thevlatter is withdrawn to permit the insertion of Aa Vfresh lead.

'I'he characteristics and advantages of the invention are further suiciently referred to` in connection with thefollowing detail description of the accompanying drawing, which shows certain respective embodiments. After considering these examples, skilled persons will understand that many variations may be made without departing from the principles disclosed, and I contemplate the employment of any structures that are properly within the scope of the appended claims.

Fig. 1 is a longitudinal section of a pencil em.- bodylng the invention in one form.

Fig. 2 is a similar section of the lower end portion, showing another operative position.

Fig. 3 is a similar view showing still another operative position. u Fig. 4 shows -the vvguide sleeve and certain co.-

operating parts in partially disassembled condition.

Fig. 5 is a detailed view of one form of operat-4 ing screw or helix.

Fig. 6 is a similar view of a modified operating screw or helix.

Referring first to Figs. 1 to 5:

In the form shown, the case or body l is of relatively thick section and may be of wood, although the case structure may be varied without affecting other features.

The operating screw or helix 2 extends throughout the greater part of the length of the case bore and may have a frictional .fit therein, which is suilicient to secure the helix against rotation.` In the form shown in Figs. 1,2 and 3, the screw consists of an originally flat strip of sheet metal, the edges of which are bent at right angles to form shallow flanges 3. This strip is wound or coiled into helical form with the flanges in contact, thus producing a wide helical channel or thread formation li to cooperate with lugs of the grip sleeve and ejecting pin, as will appear.

In the variation shown in Fig. 5, the metalr strip is formed with a, central bead 5, so that when wound to helical form, the edges of the strip abut and the successive turns of the bead 5 provide the screw channel therebetween. In the variation shown in Fig. 6, the metal strip 2a is flat without edge flanges or bead and it is Wound into helical form with an interposed wire 5, also hellcally wound and with which the edges of the strip engage, the wire in this case providing the sides of the screw thread formation or channel, the bottom of which is formed by the inner surface of the strip. l

A short sleeve or tube 6 is inserted with a frictional fit near the tip end of case l; this sleeve vbeing cylindrical and providing a chamber to receive the lead grip sleeve lug in one operative' position, as will appear.

Within the helix 2 is a longitudinally slotted guide sleeve l, the upper end of which is provided `with prongs 8 inserted and clenched in slots in the upper end 9 of a thimble I0, which is revolvable on the reduced` upper -end portion of the case and secured against kaxial displacement by a bead ii pressed in the sleeve and engaged in an angular channel ln the case. A sleeve I2 is frictionally engaged over thimble l0. Instead of a plurality of slots obviously one slot might accommodate both prongs. The outer portion of sleeve l2 receives an eraser I2a, or a cup or thimble I3 of sheet metal in which the eraser may be placed, removal of thimble I3 being prevented by pressing or spinning inward the edge I4 of sleeve I2. By the described arrangement, the guide sleeve 1 may be rotatedin relation to the case and helix 2 by turning sleeve I2.

A lead grip sleeve I5 is slidably located within the guide sleeve, and the grip sleeve has near its upper end a, closed slot I6 to accommodate a relatively long and narrow lug I1, of an ejecting pin I8, which is slidably located within the grip sleeve. The lug I8 may be formed by bending the pin, as clearly shown in Fig. 1. Below slot I6, the grip sleeve has formed thereon a relatively long and narrow lug I9, passing through the slot ofthe guide sleeve. Lug I1 also passes through the slot in guide sleeve and both the.

lugs engage in the channel of the screw or helix 2. A lower end portion of the slot in the guide sleeve is relatively narrow or constructed as at 20, Fig. 2, for frictional cooperation with lug. I9, as will appear. The lower end of the grip sleeve is slotted as at 2| to provide a lead grip.

lA metal tip 22 is fixed at the lower end of the case by providing it with an upper or sleeve portion 23 telescoping within sleeve 6 and frictionally or otherwise retained. The bore 24 at the lower end of tip 22 provides a lead guide. A lower inner portion of the tip^22 is recessed or conical as at 25, so that'when in ejecting position, the

lower end of the grip sleeve will engage in this i conical portion, the guide bore 24 to check further outward movement of the grip sleeve.

When a fresh lead has been inserted in the lead gripand the grip sleeve is withdrawn to any intermediate position Within the pencil, the grip sleeve and ejecting pin I8 are positioned as shown in Fig. 1; that is, the lower end of the` pin vI8 is withdrawn from the lower end of the grip sleeve sufficiently to permit proper' engagement of the lead end within the gripping formation of clutch of the sleeve, this proper positioning of the grip sleeve and pin being maintained by engagement of their respective lugs i1 and I9 in the screw channel. The lead is then projected as desired by rotation of sleeve I2, thus causing rotation of the guide sleeve 1 which in turn causes the lugs I 1 and I9 to rotate and to be moved downward, with maintenance of their proper spacing, as controlled by the screw channel or helix. When the end of the grip sleeve approaches the lower end of the conical formation 25 of tip 22, lug i9 passes out of the screw channel or helix and is located in the clear annular chamber provided by sleeve 6, and the grip sleeve is, therefore, permitted to remain stationary while continued rotation of sleeve l0 causes further outward movement of the ejecting pin by cooperation of its lug with the screw channel, and finally the end of the pin forces out the lead butt, as shown in Fig. 3.

Reverse rotation of sleeve I2 then first retracts the ejecting pinby movement of its lug I8 in the screw channel while th`e grip sleeve is prevented from upward movement by frictional engagement of its lug I9 in the narrow slot portion 20 of the guide sleeve. This condition continues until lug I1 engages the upper end of slot I6.I At this time, the lower end of the ejecting pin is withdrawn suiiciently to permit insertion of a fresh l'ead into the gripping end of the lead grip sleeve, and further rotation of sleeve I2 4in the reverse direction then acts by engagement of lug I1 with sleeve I5 at the upper end lof slot I6, to retract the grip sleeve longitudinally until its lug I9 is in position to again engage .in the screw channel; and thereafter both of the lugs are withdrawn toward the upper end of the case and in properly spaced relation, as above referred to, by rotary movement in the screw channel as impelled by the guide sleeve.

I thus provide in a simple vand inexpensive structure, for positive regulable projection of the lead, for positive lead butt ejection, and for convenient reloading, with definite control of the grip sleeve'and ejecting pin during reloading, and positive retraction of the grip sleeve with the lead into the pencil after reloading, all by manipulation of the one controlling element, namely, sleeve I2.

I claim:

1. A mechanical pencil comprising a casing having a reduced cylindrical end,v the cylindrical end forming a shoulder and an axial internally threaded bore in the casing coextensive with the casing and reduced end, a slotted' rotatable feed tube in the casing bore having a split end forming locking prongs, an inverted thimble journaled on said reduced end having an opening engaged by said prongs to lock the thimble and slotted tube r together, the lower` circumferential edge of the thimble riding on the shoulder, a manually operable sleeve of substantially the same outside diameter as the casing frictionally tting the outside of said thimble and projecting above the upper end thereof to conceal the end of the thimble and having its lower circumferential edge riding on the shoulder.

2. A method of producing a mechanical pencilA including laterally bending edges of a thin fiat sheet metal strip to form thin anges along each edge of the strip, then tightly coiling the flanged metal strip to form an internally threaded tubular member of small diameter and then snugly fitting the tightly coiled tube in a casing bore, the bore being of substantially the same diameter as the outside diameter of the tubular member whereby the tubular member is prevented from uncoiling and the edges of the coils are maintained in contact.

3. A mechanical pencil comprising a casing having a reduced cylindrical end, the cylindrical end forming a shoulder and an axial internally threaded bore in the casing coextensive with the casing and reduced end, a slotted rotatable feed tube in the casing bore having a split end forming locking prongs, an inverted thimble journailed on said reduced end, having an opening engaged by said prong to lock the thimble and slotted tube together, the lower circumferential edge of the thimble riding on the shoulder, and a manually operable sleeve of substantially the same outside diameter as the casing frictionally iitting the outside of said thimble and projected above the upper end thereof to conceal the end of the thimble.

4. A mechanical pencil comprising a casing having a reduced cylindrical end, the cylindrical end forming a shoulder and an axial internally threaded bore in the casing, a slotted rotatable feed tube in the casing bore having a split end forming locking prongs, an inverted thimble journalled on said reduced end, having an opening engaged by said prong to lock the thimble and slotted tube together, and a manually operable sleeve frictionally fitting the outside of said thimble and projected above the upper end thereof to conceal the end of the thimble.

5. A mechanical pencil comprising a casing having an axial internally threaded bore in the casing, a slotted rotatable feed tube in the casing 2,1os,ecs 3 bore having a split end forming locking prongs, above the upper end thereof to conceal the end an inverted thimble journalled on said reduced o! the thimble, the casing having a shoulder porend, having an opening engaged by said prong tion to provide a riding surface for the-lower to lock the thimble and slotted tube together, circumferential edge of the thimble.

and a. manually operable sleeve frictionally tting the outside of said thimble and projected PAUL S. HAUTON. 

